Bank of keys.



O. A. BALS.

BANK OF KEYS.

APPLIOATION FILED AUG. 2, 1909. REN-EWED 00125, 1911.

1,033,859. Patented July 30,1912.

2 SHEETS-SHEET 1.

WITNESSES. VVE/VTflRI mm CHARLES A. B/ms ATTORNEY,

'0. A. BALS.

BANK OF KEYS.

APPLICATION FILED AUG. 2, 1909. RENEWED 001'. 5, 1911.

\1,033,859. Patented July 30, 1912;

2 SHEETSSHEET 2.

'2 2 7 X 12 12 26 r 21 t 1s 1 8 5 7 16' o o o o o 7 A38 A2 1 A, a

WITNESSES. I Ill VE/VT'OE.

(WMM @v-VQL, CHARLES A. BALS A T TORIVE).

State of Illinois,

- manufacture in such keys.

] earner union oHenLEs A. BALS, or onr'caeo, rumors, assren'on r0. eoRwINsErEPHonE MANU- FACTUR-ING COMPANY, OF CHICAGO,

BANK OF KEYS.

ILLINOIS, A CORPORATION OF ILLINOIS.

messes.

Specification of Letters Patent. 3 Patented July .30, 1912.

Application filed August z, 1909, {Serial No. 510,84l4. Renewed October 5, 1911. Serial No. 652,959.

To all whom it may concern:

Be it known that I, Gr rannns A. BALs, a citizen of the United States of America, residing at Chicago, in the county of Cook and 1 have invented anew and; useful Bank of Keys, of which the following is a specificatiomreference being had to the accompanying drawings, illustrating same.

y invention relates to electrical switching mechanism, and in particular to banks of switch keys preferably of the push-button type. v

The principal objects of my invention are, to provide an improved switching arrangement for such a bank of keys, and improved means for operating such switching mecha nism; to provide an improved construction in such a bank of keys and in the various parts thereof; and to provide simplicity of construction, accessibility and cheapness. of

Other objects will be apparent from the, following specification.

In banks-of keys heretofore made, there have been employed certain parts made of heavy metal pieces, such as castings or machined portions, to fill the various requirements. This generally produces asomewhat cumbersomebank of keys and also makes thecostof manufacture very high. In the present invention I have constructed a bank of keys almost entirely of parts punched and formed from sheet metalfthereby producing a bank of keys which has a very neat appearance and which is very much'cheaper, to manufacture than keys heretofore made.

In this invention I have also provided switches near one end of the bank of keys, and have arranged the latch frame for the various plungers to operate these switches, thereby greatly simplifying the 'construc tion ofthe keys and doing'aw aywith a great many switch-contact members usually emp'loyed' in such keys. The switches at the end of the bank of keys, which are operated by thelatch frame, are preferably used as' common ringing switches, especially in intercommunicating telephone systems, but of course these switches may be used for any desired purpose or purposes.

In the accompanying drawings illustrating the preferred form of my invention, Figure lis a side elevation of the improved bank =of'keys, with a'portion of the,latch frame removed; Fig. 2 is an end eleii'ation of the the bank of keys; Fig.

bank of ke 's shoyvn in Fig. 1; Fig. 3 is an end View 0 the bank of keys shown in Figs. 1 and 2, with theend port-ions removed to show the construction of switches; Fig. 4: is a plan view-ofthe top plate ofthe bank of keys; ,fi is' a plan view of the improved latch frame used in 6 is a side elevation of one of the switch-contact mounting bars of the bank of keys, with a portion cut away to show the \bearing for the lower ends of the plungers; Fig. 7 is a cross-sectional view of the-bar shown in Fig. 6, taken on plan a: a; of Fig. 6; Fig. &is a side elevation of the improved sheet metal plunger usedin the bank of keys; and Fig. 9 is an edge eleigation of the improved plunger shown in ig. 8.

Like characters refer to like parts in the several figures.

the plungers and .60

ger when same is thrown up lthrough the plate 1. v

At each end of the bank of keys is provided a formed sheet metal portion 5 adapted to be mounted to a suitable support at their lower. outturned ends 6 6. Mounted between the end plates 5 5 are one or more bars 7 7 carrying sets of switch-contactmembers 8 8 9 9, preferably as shown, these switch-contact members being suitably in- ;sulated from each other and also from the .barS 7 7.

Each of the plungers 2 2 carries an insulatingportion 10 adapted to pr ss thecorresponding spring members 8 8 outwardly intoengagement with" the corresponding spring. members 9 9 respectively, when the thumb piece-'11 of the depressed; These switch springs or contacts may extend to any suitable circuits, in some instances some of them being connected in common through the bank of keys. They may if desired be connected so as to connect a telephone set with a plurality of telephone lines, as is generally done 1n an intercommunicating telephone system.

Each of the bars 7 7 is provided withi'a series of holes 12 in the upper edge thereof, to accommodate the lower ends of the plungers 2 2, thev 7 7 being also recessed plunger is properly as at 13 to provide a Short bearing at 12 for the ends of the plungers. This construction greatly reduces the friction on the plungers 2 2 and thereby gives them an easier action.

The plungers 2 2 are preferably formed .out of sheet metal as shown in Figs. 8 and 9, the upper endshaving screw threads 1 1 formed thereon for connecting the thumb pieces 11 with the plungers. The lower portions 15 15 of the plungers 2 2 are preferably rounded off to provide a round pin.

These plungers 2 2 can be readily formed in suitable dies without having any machine work done thereon.

The latch frame illustrated, and shown more in detail in Fig:'5,'is formed from a piece of sheet metal. It comprises a pair of upturned side portions 1616 adapted to slide in suitable notches in the end plates 5 5 preferably as shown, and a plurality of cross-strips 17 17 each of which is formed with an upturned edge portion 18 preferably as shown. The upturned edge portions 18 18 fit in notches 19' 19 in the plungers -2 2 when the latter are in their raised positions. When, however, one of the plungers 2 2 is depressed so as to cause the corresponding spring members 8 8 to engage the corresponding spring members 9 9 respectively, the latch plate is moved in the direction of arrow 20 until the plunger is deressed far enough to allow the correspondlng portion 18 to slip back into the upper notch 21 in the plunger 2 which is being depressed. The latch'frame is moved in the direction of arrow 22 by one or more spring members 23 23 which bear against moved in the direction of arrow 20 so that any'of the other plungers which may have been depressed are thereby'released, the corp responding springs 25 25 then throwingthem to their uppermost position. Thus it will be seen that depressing any, of the plungers to locking position releases any of the other plungers which may have been previously locked in depressed position.

The notches 21 21 in the plungers 2 2 have beveled upper edge portions 26 26 adapted to move the latch frame in the direction of arrow '20 and thereby release any of the other plungers which may have been locked in depressed position. These beveled surfaces 26 .26 are long enough so that by depressing any of the plungers 2 2 past locking position the latch frame may be moved in the direction of arrow 20 somewhat farther than by merely depressing the.

plungers to locking position. This farther movement of the latch frame causes the spring members 23 23 to engage corresponding spring members 27 27, to close suitable circuits as desired, the s ring members 23 23 and 27 27 being pre erably mounted on one of the end plates 5 5 by means ofsuitable mounting plates 28 28 secured to'the end plate 5, the springs 23 23 and 27 27 being suitably insulated from each other and from the plates 28 28. Each of the springs 23 23 is preferably provided with a heavy terminal member 29 electrically connected therewith as shown. Of course it will be readily understood that the spring members 23 23 may be made to operate any number of switch contacts in any manner desired, to control suitable circuits. It will be readily. seen that this arrangement of causing the latch frame to operate suitable switch contacts, by depressing the plungers 2 2 past locking position, does away with a great many individual contact members for the various keys, as where each key is caused to control individual contact members by a depression thereof past locking position. I

At one end of the bank of keys is preferably mounted a strip of insulation 30 carrying a plurality of-terminal members 31 31 which may be suitably connected to the terminals of the bank of keys as desired.

It will be readily understood that the latch frame may operate its switches to control suitable circuits, either when a plunger is depressed to locking position, or depressed past locking position, whichever is desired.

It will readily be seen that by making the top plate 1, the plungers 2 2, the end plates 5 5, and the latch frame, all out of sheet metal, a bank of keys is provided which is very simple in its construction, very durable, and very cheap to manufacture.

I do not wish to limit this invention to all of the particular details herein setforth, as various modifications of same may be made without departing from the scope of the apended claims.

What I claim as my invention is:

1. In switching apparatus of the character described, the combination with a supporting frame, of a plurality of actuating plungers carried thereby, suit-able switch contacts for each of the plungers and adapted to be operated thereby, a latch frame adapted to be actuated by the depression of" any of the plungers to switching position,

means for causing the latch frame to lock.

the plungers in the aforesaid depressed position, switch cont-acts adapted to be operated by the latch frame, and means whereby a further depression of any of the plungers Copies this patent may be obtained for five cents each, by addressing the Commissioner of .Patents.

Washington, D. 0.

past lockingposition movesthe said latch frame still farther in a longitudinal direc tion and thereby causes same t6 operate the position and being capable of being depressed past locking position, a latch frame adapted to lock the plungers in locking position, the said -plungers being adapted to operate the said switches when depressed to locking position, and also to give the said latch. frame a longitudinal movement,

switching mechanism adapted to be operated by the said latch frame, and means whereby a further depression of any ofthe plungers past locking position gives the said latch frame a greater longitudinal movement whereby it is caused to operate its saidswitching mechanism.

3. In switching apparatus of the character described, the combination .with a supporting frame, of a plurality of actuating plungers carried thereby, switching mechanism for each plunger adapted to be operated thereby, a latch frame adapted to lock the plungers in depressed position, means upon depression of a plunger to locking po sition for causing simultaneous actuation of the latch frame for purposes substantially as described, switching mechanism adapted to be operated by the said latch frame, and means whereby a further depression of any of the lungers'past locking position gives the said latch frame an extreme longitudinal movement whereby it is caused to operate its said switching mechanism.

4'. In switching pparatus of the character described haiiing a plurality of plungers and switches adapted to be 0 erated thereby, a' latch frame for theungers whereby the latter may be locke in depressed position, switching mechanism adapted to beoperated by the latch frame and means whereby a further depression 6f I a plunger ast locking position gives the said latch ame a longitudinal movement to cause same to operate its switching mechanism.

scribed, a suit-able rame, mounting bars carried by the said frame and carrying sets of spring members, aplurality of plungers for operatinlg1 the said spring members upon depression t v ing an opening in an edge thereof, into which openin the ends of the said lungers extend, t e said mounting bars eing'. recessed from one side thereof to meetthe said openings therein whereby the bearings for the said inserted ends of the lungers are reduced as desired, substantially as described.

As inventor of the foregoing I hereunto subscribe my name this 31st day of July,

, CHARLES A. BALS; Witnesses:

FRANCES K. PARKER, FREDERICK R. PARKER.-

5. In a bank of keys of the character de- 

